Effect of pulsed and spray multipass MAG welding on the corrosion resistance of 316L stainless steel

Abstract

In this study, the corrosion resistance of the ASTM A-240 TP 316L stainless steel submitted to a multipass metal active gas (MAG) welding was investigated. The stainless steel was MAG welded in two modes of metal transfer: pulsed and spray with protective gas (98% Argon and 2% Oxygen). The microstructure and corrosion resistance of base metal (BM) and fusion-zone (FZ) were characterized by scanning electron microscopy (SEM), ferritescope test, and anodic polarization tests. All zones were passive in the test solution (NaCl 1.0 mol L-1) followed by passive film breakdown with a potential increase. The BM showed a higher tendency to film breakdown comparatively to the FZ. The FZ in the spray process presented a passive film with higher breakdown resistance than the pulsed FZ.